<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #box{
            width: 200px;
            height: 200px;
        }
    </style>
</head>
<body>
    
  <div id="box"></div>
    <script>

var box = document.getElementById('box')
        function add(x, y) {
            console.log(x + y);
            console.log(this, 'rrrrr');
            this.style[x] = 'red'
        }

        function minus(x, y) {
            console.log(x - y);
        }

        // add.call(box, 'backgroundColor'); //2 
        var a = add.bind(box, ['backgroundColor'])
        a()
        console.log(a,'aaaaaaaaaa');
    </script>
</body>
</html>